In a unique spherical world, a one-of-a-kind black cat is born. Enduring hunger, the oppression from other cats and dogs, and even the threat of giant mice—can this little feline grow up strong against all odds? Take control of this adorable black cat, learning skills from everyone you defeated and guide it to become the ultimate ruler of the world!
\nBasic Controls:
\nMouse Control: Drag the mouse to move the black cat in your desired direction.
\nWinning Goal: Keep growing until your cat’s diameter exceeds the map width (which is 2000 units) to claim victory!
\nEnemy Types:
\nDog Balls: Recognizable by their brown color.
\nMouse Balls: Distinguished by their dark gray color.
\nCat Balls: Identified by their pink color.
\nPredator-Prey Relationships:
\nBlack Cat (You): Can eat smaller dog balls, mouse balls, and cat balls.
\nDog Balls: Will actively chase and hunt smaller mouse balls and cat balls.
\nMouse Balls: Have a defensive instinct—they will avoid larger dog balls and cat balls.
\nCat Balls: Tend to chase and attack smaller mouse balls and dog balls.
\nUniversal Behavior: All enemies will try their best to avoid being eaten by larger balls, so stay alert to their evasive movements!
\nSkill System:
\nEating different types of enemy balls grants your black cat unique skills—use them wisely to gain an edge!
\nDash Skill (⚡): Eat mouse balls to unlock this skill. It lets your cat dash quickly in the current movement direction, great for escaping danger or chasing prey.
\nRoar Skill (🚫): Consume dog balls to obtain this skill. Activating it creates a red circle that freezes all enemies in place for 3 seconds, buying you time to either escape or eat smaller targets.
\nDouble Score Skill (×2): Eat cat balls to get this skill. When activated, it doubles your earned points for 5 seconds, helping you boost your score rapidly.
\n","source":"skyatmoon/js13k2025","stars":1,"comments":[{"at":410652267,"author":"xem","login":"xem","gh":1225909,"text":"Nice reinterpretation of this famous online game (I forgot the name), with cats!\nIt’s cute and has good music too. The movement is a bit too fast maybe.
\n","games":["I got up on the wrong foot"]},{"typ":1,"at":411000063,"re":410652267,"author":"skyatmoon","login":"skyatmoon","gh":53244544,"text":"THX a lot! Maybe you mean Osmos? A bit idea comes from this. If you becomes bigger, maybe you well feel too slow ρ(・ω・、)
\n"},{"at":410737826,"author":"Cliff Earl","login":"Antix-Development","gh":17822130,"text":"I didn’t think I’d enjoy this but it was really good. So easy and rewarding. A lot could be done to enhance it.
\n","games":["Black Cat - Nine Lives, No Mercy"]},{"typ":1,"at":410999205,"re":410737826,"author":"skyatmoon","login":"skyatmoon","gh":53244544,"text":"Thanks for your time and suggestions! Easy but happy for players love it is a game I think should do!
\n"},{"at":410901893,"author":"Zang0l0tino","login":"Zang0l0tino","gh":167128079,"text":"Nice game, when I grew big I passed from being super fast to really slow; and the arrow didn’t point exaclty at the end. Apart from that, I think the beginning is too fast, but the game is great overall.
\n","games":["The Black Cat's Escape"]},{"typ":1,"at":410999083,"re":410901893,"author":"skyatmoon","login":"skyatmoon","gh":53244544,"text":"lol, thx for your love! At begining I just want to build a cat running game, but finally game becomes to this (›´ω`‹ )
\n"},{"at":410921235,"author":"F肯尼","login":"kennyfully881230","gh":208875314,"text":"The game was very interesting! I like the fast pace of the game! Thank you very much!
\n","games":["Heimao"]},{"typ":1,"at":410998671,"re":410921235,"author":"skyatmoon","login":"skyatmoon","gh":53244544,"text":"Thanks a lot for your love! lol Have fun!
\n"},{"at":411108539,"author":"Michael M.","login":"Schnark","gh":17846729,"url":"https://schnark.github.io","text":"The difficulty varies very much with the size of the browser window. When I first played with my normal sized window, enemies just appeared so fast that I had no time to avoid them. With a larger window it became easier.
\n","games":["Edgar's Mission"]},{"at":411170797,"author":"Homer Dilpleu","login":"HomerDilpleu","gh":66157330,"text":"Good remake of agar.io, it perfectly works! At the beginning, when the cat is very small, the speed was to high for me. Nice game, congratulations!
\n","games":["Wash the cat"]},{"at":411175246,"author":"Anthony Cosgrave","login":"anthonycosgrave","gh":1410114,"url":"https://imtoospexy.com/","text":"The graphics are good and so is the music. I’m not quite sure I understood the point of the game, I feel like I was just holding down the mouse and traveling around the screen very fast.
\n","games":["Chickpocalypse Meow"]},{"at":411199369,"author":"Attila Horváth","login":"attilahorvath","gh":4081005,"text":"Decent implementation of the agar.io style games but with some balancing issues.
\nIt is way too fast when you start the game and you’re still small, enemies can just rush you from nowhere and so easy to lose at this stage. On the other hand when you get large, it becomes very slow and I felt like nothing can really hurt me anymore. There is a big chunk of the screen covered by the tutorial, limiting my view. Would be great if you could close that.
\nNice job on the enemy behaviours and the different types. Also, the different skills add depth to the game. The music is simple but pleasant.
\nGood job overall, keep it up!
\n","games":["A Voiding Your Problems"]},{"at":411214511,"author":"Elias Ku","login":"eliasku","gh":3038174,"url":"https://eliasku.win","twitter":"eliaskuvoice","text":"Great idea! Really cool cat. It’s very satisfying to collect them, and having smaller creatures to chase gives the game an interesting and engaging start. You might want to fine-tune the speed balance between the enemies and the player character at different stages of the game.
\nIt’s a bit surprising that this wasn’t developed as an Online category entry - was it a matter of time constraints? In any case, it’s a highly entertaining game. Good job! 👏😺
\n","games":["Cat Survivors"]},{"at":411350248,"author":"Jonathan Vallet","login":"jonathan-vallet","gh":5329099,"text":"⚖️ At the start, the character is way too fast, and then becomes too slow after reaching a certain size. The agar.io style with a spherical world is pretty cool though!
\n","games":["Witchcat"]},{"at":411437219,"author":"Surma","login":"surma","gh":234957,"url":"https://surma.dev","text":"Really interesting take on agar.io. Congratulations on building a multiplayer game, too! That’s a great technical achievement.
\nI The controls were a bit unwieldy and fast for me on a laptop with a trackpad, and the music was a bit too minimalist for my taste. I wish the growth when eating food would be more visible, I wasn’t sure if anything was happening.
\n","games":["Swing A Cat"]},{"at":411694097,"author":"Jasper Renow-Clarke","login":"picosonic","gh":26137750,"twitter":"femtosonic","text":"Easy to play, and fun
\nThe audio was good
\nReminds me of an online game where you are a growing snake
\nI didn’t notice my character getting any bigger despite collecting loads of the smaller balls
\nJust to note, when you do mute the music, it restarts when you die even if it’s still set as mute
\n","games":["Mochi and the midnight escape"]},{"typ":2,"at":411755664,"author":"Noël Meudec","login":"Noel-FB","gh":71314518,"url":"https://facebook.com/instantgames","text":"This game is very similar to Hole.io.\nIt works well, with IA controlled enemies, good game mechanics and all.\nI reached a size of 300 and stopped because I became way to slow! Maybe there is something to tweak so the feeling of speed is better managed. Also, I played on a trackpad; the fact that I had to constantly press on it to move was tiring. Maybe clicking could switch between moving mode and static mode? To make the game better, I would also add visual effects and sounds effects.\nOverall, it is great implementation of Hole.io, with all the expected game mechanics implemented (and enemy AI), which is quite impressive.
\n"}],"results":{"theme":{"rank":142,"min":1,"score":2.4,"max":4.24},"innovation":{"rank":161,"min":1.2,"score":2.05,"max":4.03},"gameplay":{"rank":84,"min":1.18,"score":2.85,"max":4.37},"graphics":{"rank":148,"min":1.6,"score":2.35,"max":4.56},"audio":{"rank":100,"min":1.75,"score":2.45,"max":4.22},"controls":{"rank":138,"min":1.6,"score":2.7,"max":4.45},"primary":{"rank":124,"min":8.68,"score":14.8,"max":24.89},"label":"Overall"}}